Pouch for a pressurized bottle

ABSTRACT

The invention relates to a pouch for a pressurized bottle, made up of a tubular wall closed in its upper part by a welded seam into which a valve is incorporated. According to the invention, the tubular wall is obtained by overlapping and welding together the two lateral edges of a strip, and the tubular wall is closed in its lower part by an essentially round bottom wall. Thus, the tubular wall of the pouch will have a practically circular cross section in a large lower part, this cross section tending towards an elliptical shape as it nears the upper end where it becomes completely flat. The pouch will, at least in a major lower part, occupy practically all the space in the bottle, considerably reducing the dead space in that part.

The invention concerns a pouch for a pressurised bottle according to the precharacterising clause of the main claim.

Such pouches are commonly used in cosmetic, food and technical-product atomisers. They separate the product to be applied from the propellant gas contained in the bottle.

They generally consist of two walls welded together by four welds, a valve being integrated in the top weld to enable the content of the pouch to be taken off.

Once filled, these pouches therefore have an oval or elliptical transverse section. The two lateral welds each form a projecting edge that requires oversizing the bottle in order to leave space for them. Likewise, the bottom of the pouch is also flattened and is appreciably distant from the wall of the bottle. In other words, the dead space inside the bottle due to the geometry of the pouch is not insignificant.

From the document FR 2 853 633 A1 a pouch for a non-pressurised bottle is known, the cylindrical central part of which is formed by rolling a rectangular laminated film and bonding the opposite sides together. This pouch is closed at the bottom by a thick plate to which it is connected by welding. The top part of the pouch is welded to a circular collar onto which a pumping device can be snapped. When the product is taken off, a negative pressure forms in the pouch, which contracts. However, the bottom plate prevents complete contraction of the pouch because of its rigidity. In addition, it is not possible, still because of this thick bottom plate, but also the top collar, to wind the pouch on itself along its longitudinal axis for example in order to facilitate its introduction into a bottle having a smaller insertion neck or to reduce the storage volume before assembly.

The objective of the invention is therefore firstly to reduce the number of welds necessary for manufacturing the pouch and secondly to reduce the dead space inside the bottle in order to increase the filling ratio while keeping a pouch that is sufficiently flexible to be able to be wound on itself in order to facilitate its insertion in a bottle.

This objective is achieved according to the invention because the tubular wall is obtained by overlapping and welding the two lateral edges of a strip. Thus the tubular wall of the pouch will have an almost circular transverse section over a large part of its height. Moreover, the projecting edges of the pouches of the prior art are avoided. In addition, there is now only one longitudinal weld, where two were necessary with the known pouches of the prior art.

It is preferable for the part of the lateral weld to be situated at one of the ends of the top weld of the tubular wall.

In a first embodiment of the invention, the tubular wall is closed in its bottom part by welding the bottom edge of the wall flat, preferably in the same plane as the top weld including the valve. This first embodiment is particularly simple to implement. The transverse section of the pouch is almost circular halfway up the height of the pouch, this section tending to become elliptical when approaching the top and bottom ends, where it is totally flat. The pouch occupies, at least in its central part, a major part of the space of the bottle, considerably reducing the dead space in this part.

In a second embodiment, the tubular wall is closed in its bottom part by an essentially round bottom wall. Thus the circular transverse section extends as far as the bottom part of the pouch, tending to become elliptical when approaching the top end, where it is totally flat. The pouch occupies, at least in a major bottom part, practically all the space of the bottle, considerably reducing the dead space in this part.

To enable the pouch to be wound on itself along the longitudinal axis of the tubular wall, it is preferable to produce the bottom wall from a flexible material, preferably the same material as that used for the tubular wall. By choosing the same material, management of the manufacture is facilitated and problems of welding incompatibility are avoided. It is thus possible to reduce the storage volume for the pouches before they are introduced into the pressurised bottles and to facilitate introduction thereof into these bottles when the neck of the bottles is relatively narrow.

It is preferable in this case for the bottom wall to be essentially flat and perpendicular to the longitudinal axis of the pouch. This is the solution that is the most simple to implement. The bottom wall is preferably fixed to the internal face of the tubular wall, in particular by means of a folded-over edge.

In accordance with the invention, it is preferable for the tubular wall to consist of a metal/plastic film, preferably aluminium associated with polypropylene, high- or low-density polyethylene, EVOH (ethylene vinyl alcohol) and/or Orgaloy® (a mixture of polyamide and polypropylene).

The invention is described in more detail below with the help of the figures, which show:

FIG. 1: a perspective view of a first example embodiment of a pouch according to the invention;

FIG. 2: a front view of the pouch of FIG. 1;

FIG. 3: a view in section along the line A-A in FIG. 2;

FIG. 4: a side view of the pouch of FIG. 1;

FIG. 5: a perspective view of a second example embodiment of a pouch according to the invention;

FIG. 6: a front view of the pouch of FIG. 5;

FIG. 7: a view in section along the line A-A in FIG. 6;

FIG. 8: a side view of the pouch of FIG. 5;

FIG. 9: a partial cross section of the bottom of the pouch of FIG. 5.

In both embodiments, the pouch (1, 101) of the invention consists of a tubular wall (2, 102). This tubular wall is obtained by welding the two lateral edges of a strip, these two edges overlapping. The longitudinal weld (23, 123) is therefore made by applying the internal face of one of the edges to the external face of the other end of the strip. This weld is therefore in line with the tubular wall without projecting as is the case in the prior art, where the two edges are welded by putting the internal faces of the edges of the strip face to face.

The tubular wall (2, 102) consists of a strip closed on itself for example by a weld so as to obtain a circular transverse section without a projecting edge.

The top end (22, 122) is closed by flattening the tubular wall in order to weld it on itself. An aerosol valve (4, 104), known per se, is placed at the centre of this weld (22, 122) to enable the product contained in the pouch (1, 101) to be taken off.

The choice of material will for example be a metal/plastic film such as aluminium associated with polypropylene, high-or low-density polyethylene, EVOH (ethylene vinyl alcohol), or Orgaloy® (a mixture of polyamide and polypropylene).

This pouch is intended to be introduced into a dispensing bottle. The valve serves to take off the content of the pouch. A gas or other propellant contained in the receptacle, outside the pouch, serves to propel this content through the valve as soon as the latter is actuated.

In the first embodiment of the invention, the tubular wall (102) is closed at its bottom end (121) by welding the bottom edge (121) of the wall flat. The top weld (122) and the bottom weld (121) are preferably in the same plane, although this is not obligatory. The longitudinal weld (123) is preferably placed at one of the ends of the bottom (121) and top (122) welds.

In the second embodiment, the tubular wall (2) is closed at its bottom end (21) by a substantially round bottom wall (3) produced from a flexible material, preferably the same material as that used for the tubular wall.

The bottom wall (3) is fixed for example by welding to the bottom end (21) of the pouch (2). This bottom wall (3) is essentially flat and extends in the plane perpendicular to the longitudinal axis of the pouch (1). It will be possible for example to weld it by folding downwards the periphery of the bottom wall (3) so that a projecting edge (31) forms parallel to the longitudinal axis of the pouch, as shown by FIG. 9.

The advantage of this pouch, whether it is a case of the first embodiment or the second, is to require only three welds instead of four in the pouches of the prior art. In addition, the shape of the pouch is essentially cylindrical in a large part of its height rather than oval or elliptical as in the prior art. In addition, the absence of the longitudinal welds flat over the entire height of the pouch makes it possible to effectively reduce the dead space in the bottle. This affords a better filling ratio. This is because the tubular wall is to a great extent cylindrical and therefore is better aligned with the wall of the receptacle in which it is to be inserted.

LIST OF REFERENCES

-   101 Pouch -   102 Tubular wall     -   121 Bottom end     -   122 Top end     -   123 Lateral weld     -   104 Valve -   1 Pouch -   2 Tubular wall     -   21 Bottom end     -   22 Top end     -   23 Lateral weld -   3 Bottom wall     -   31 Folded-over edge -   4 Valve 

1. Pouch for a pressurised bottle composed of flexible tubular wall closed in its top part by flattening the tubular wall in order to weld it on itself, an aerosol valve being integrated in the weld, characterised in that the tubular wall is obtained by overlapping and welding the two lateral edges of a strip.
 2. Pouch according to claim 1, wherein the top part of the lateral weld is situated at one of the ends of the top weld of the tubular wall.
 3. Pouch according to claim 1, wherein the tubular wall is closed in its bottom part by welding its bottom edge flat.
 4. Pouch according to claim 3, wherein the bottom weld and top weld are substantially in the same plane.
 5. Pouch according to claim 1, wherein the tubular wall is closed at its bottom part by an essentially round bottom wall.
 6. Pouch according to claim 5, wherein the bottom wall is produced from a flexible material, preferably from the same material as that used for the tubular wall.
 7. Pouch according to claim 5, wherein the bottom wall is essentially flat and perpendicular to the longitudinal axis of the pouch.
 8. Pouch according to claim 5, wherein the bottom wall is fixed to the internal face of the tubular wall.
 9. Pouch according to claim 1, wherein the bottom wall is fixed to the tubular wall by a folded-over edge.
 10. Pouch according to claim 1, wherein the tubular wall consists of a metal/plastic film, preferably aluminium associated with polypropylene, high- or low-density polyethylene, EVOH (ethylene vinyl alcohol) and/or Orgaloy® (a mixture of polyamide and polypropylene).
 11. Pouch according to claim 2, wherein the tubular wall is closed in its bottom part by welding its bottom edge flat.
 12. Pouch according to claim 2, wherein the tubular wall is closed at its bottom part by an essentially round bottom wall.
 13. Pouch according to claim 12, wherein the bottom wall is produced from a flexible material, preferably from the same material as that used for the tubular wall.
 14. Pouch according to claim 6, wherein the bottom wall is essentially flat and perpendicular to the longitudinal axis of the pouch.
 15. Pouch according to claim 12, wherein the bottom wall is essentially flat and perpendicular to the longitudinal axis of the pouch.
 16. Pouch according to claim 13, wherein the bottom wall is essentially flat and perpendicular to the longitudinal axis of the pouch.
 17. Pouch according to claim 6, wherein the bottom wall is fixed to the internal face of the tubular wall.
 17. Pouch according to claim 7, wherein the bottom wall is fixed to the internal face of the tubular wall.
 19. Pouch according to claim 17, wherein the bottom wall is fixed to the tubular wall by a folded-over edge.
 20. Pouch according to claim 18, wherein the bottom wall is fixed to the tubular wall by a folded-over edge. 